1. Field of the Invention
The present invention relates to a flyback transformer which is used in a television receiver and other devices, and more particularly, to the structure of an anode lead wire used for connecting the flyback transformer and a cathode ray tube (CRT).
2. Description of the Related Art
Hitherto, flyback transformers have been installed in television receivers or display apparatuses. In such an application, a high output voltage is applied from high-tension coils (e.g., secondary coils) used in the flyback transformers to anodes used in cathode ray tubes through anode lead wires. In recent years, a so-called anode-lead-wire-post-mounting technique has become prevalent as a step in the assembly of television receivers and like display apparatuses. In this process, the anode lead wire is mounted to the flyback transformer after the flyback transformer has been installed in the television receiver or display apparatus so as to facilitate assembly.
FIG. 6 shows the connection mechanism of an anode lead wire in a conventional flyback transformer produced by the above-described technique of anode-lead-wire-post-mounting. The connection mechanism used to connect the anode lead wire 51 is mainly composed of the anode lead wire 51, an anode lead holder 52 and a conductive rubber member 53 (e.g., conductive rubber member 53 may comprise rubber or other resilient material with conductive material added thereto). The anode lead holder 52 is formed in a cylindrical shape and is made of an insulating resin material. The anode lead holder 52 has engagement pieces 54 having resilient properties when extended in an inward (radial) direction. The engagement pieces 54 project from the inner surface of the anode lead holder 52. The anode lead wire 51 is inserted from one opening (the right end in FIG. 6) of the anode lead holder 52, and the conductive rubber 53 is pressed into the other opening (the left end in FIG. 6) and fixed thereto. A high-voltage lead wire 58 for providing a high voltage output from a high-tension coil (e.g., a secondary coil) is thrust into the conductive rubber 53. The inner diameter "b" of the anode lead holder 52 is defined by the size of a connecting fitting 57 mounted to the head of the anode lead wire 51.
As shown in FIG. 7, an insulating film 55 at the head of the anode lead wire 51 is removed to expose a core wire 56. In addition, a metal connecting fitting 57 is attached to the head. To attach the connecting fitting 57 to the anode lead wire 51, the edges of the connecting fitting are tapered so that they cut into and engage the insulting film 55. Also, the core wire 56 and connecting fitting 57 are secured by solder 59.
A series of operations used to secure the anode lead holder 52 to the anode lead wire 51 will now be described. The anode lead wire 51 having the connecting fitting 57 attached to the head thereof is first inserted from one opening (e.g., the right opening) of the anode lead holder 52. When the connecting fitting 57 engages the engagement pieces 54, the connecting fitting 57 is advanced so as to gradually expand the space between the tips of the engagement pieces 54, and the head of the core wire 56 is thrust into the conductive rubber 53. When the connecting fitting 57 is advanced such that the portion thereof which cuts into the insulating film 55 passes the tips of the engagement pieces 54, the engagement pieces 54 return to their original state as a result of the elastic restoring force thereof. In this state, the engagement of the connecting fitting 57 with the engagement pieces 54 allows the anode lead wire 51 to be retained. That is, the engagement pieces 54 thereby prevent the anode lead wire 51 from falling out, so that the anode lead wire 51 is held and fixed to the anode lead holder 52.
The conventional flyback transformer encounters at least the following problems.
The connecting fitting 57 is required to be attached to the head of the anode lead wire 51, so that the number of components is increased and the operation of mounting the connecting fitting 57 requires much labor, resulting in an increase in cost.
In addition, it is necessary to widen the inner diameter "b" of the anode lead holder 52 to accommodate the relatively large size of the connecting fitting 57, resulting in an increase in size of the anode lead holder 52.